Spatial Neglect Subtypes, Definitions and Assessment Tools: A Scoping Review

Gaze Scanning on Mid-Block Sidewalks by Pedestrians With Homonymous Hemianopia With or Without Spatial Neglect

Purpose

The purpose of this study was to investigate gaze-scanning by pedestrians with homonymous hemianopia (HH) when walking on mid-block sidewalks.

Methods

Pedestrians with right homonymous hemianopia (RHH), and left homonymous hemianopia (LHH) without and with left spatial neglect (LHSN) walked on city streets wearing a gaze-tracking system. Gaze points were obtained by combining head movement and eye-in-head movement. Mixed-effects regression models were used to compare horizontal gaze scan magnitudes and rates between the side of the hemi-field loss (BlindSide) and the seeing side (SeeingSide), among the three subject groups, and between mid-block walking and street crossing segments.

Results

A total of 7021 gaze scans were obtained from 341 minutes of mid-block walking videos by 19 participants (6 with LHH, 7 with RHH, and 6 with LHSN). The average gaze magnitude and scanning rate in mid-block segments were significantly higher towards the BlindSide than the SeeingSide in LHH (magnitude larger by 1.9° (degrees), P = 0.006; scan rate higher by 4.2 scans/minute, P < 0.001) and RHH subjects (magnitude larger by 3.3°, P < 0.001; scan rate higher by 3.2 scans/minute, P = 0.002), but they were not significantly different in LHSN subjects. The scanning rate, in terms of scans/minute (mean, 95% confidence interval [CI]) was significantly lower in LHSN subjects (mean = 6.9, 95% CI = 5.6-8.7) than LHH (mean = 10.2, 95% CI = 8.0-13.1; P = 0.03) and RHH (mean = 11.1, 95% CI = 9.0-13.7; P = 0.007) subjects. Compared to street-crossings, the scan rate during the mid-block segments was lower by 3.5 scans/minute (P < 0.001) and the gaze magnitude was smaller by 3.8° (P < 0.001) over the 3 groups.

Conclusions

Evidence of compensatory scanning suggests a proactive, top-down mechanism driving gaze in HH. The presence of spatial neglect (SN) appeared to negatively impact the top-down process.

A scoping review and critique of the Input-Output subtyping dimension of spatial neglect

Spatial neglect is a common and debilitating disorder after stroke whereby individuals have difficulty reporting, orienting, and/or responding to the contralesional side of space. Given the heterogeneity of neglect symptom presentation, various neglect subtypes have been proposed to better characterize the disorder. This review focuses on the distinction between Input neglect (i.e., difficulty perceiving and/or attending to contralesional stimuli) and Output neglect (i.e., difficulty planning and/or executing movements toward contralesional stimuli). Conceptualizations of Input and Output neglect have varied considerably. We provide a novel summary of the terminology, measurement approaches, and neural correlates of these subtypes. A protocol detailing our systematic scoping review strategy is registered on the Open Science Framework (https://osf.io/bvtxf/). For feasibility and greater comparability across studies, we limited our inclusion criteria to tasks focused on visual stimuli and upper-limb movements. A total of 110 articles were included in the review. Subtyping tasks were categorized based on whether they mainly manipulated aspects of the input (i.e., congruence of visual input with motor output, presence of visual input) or the output (i.e., modality, goal, or direction of output) to produce an Input-Output subtype dissociation. We used our review results to identify four main critiques of this literature: 1) lack of consistency/clarity in conceptual models; 2) methodological issues of dissociating Input and Output subtypes; 3) a need for updated neural theories; and 4) barriers to clinical application. We discuss the lessons learned from this subtyping dimension that can be applied to future research on neglect subtype assessment and treatment.

An International and Multidisciplinary Consensus on the Labeling of Spatial Neglect Using a Modified Delphi Method

Survivors of neurologic injury (most commonly stroke or traumatic brain injury) frequently experience a disorder in which contralesionally positioned objects or the contralesional features of individual objects are often left unattended or underappreciated. The disorder is known by >200 unique labels in the literature, which potentially causes confusion for patients and their families, complicates literature searches for researchers and clinicians, and promotes a fractionated conceptualization of the disorder. The objective of this Delphi was to determine if consensus (≥75% agreement) could be reached by an international and multidisciplinary panel of researchers and clinicians with expertise on the topic. To accomplish this aim, we used a modified Delphi method in which 66 researchers and/or clinicians with expertise on the topic completed at least 1 of 4 iterative rounds of surveys. Per the Delphi method, panelists were provided with results from each round prior to responding to the survey in the subsequent round with the explicit intention of achieving consensus. The panel ultimately reached consensus that the disorder should be consistently labeled spatial neglect. Based on the consensus reached by our expert panel, we recommend that researchers and clinicians use the label spatial neglect when describing the disorder in general and more specific labels pertaining to subtypes of the disorder when appropriate.

Advancements in brain-computer interfaces for the rehabilitation of unilateral spatial neglect: a concise review

This short review examines recent advancements in neurotechnologies within the context of managing unilateral spatial neglect (USN), a common condition following stroke. Despite the success of brain-computer interfaces (BCIs) in restoring motor function, there is a notable absence of effective BCI devices for treating cerebral visual impairments, a prevalent consequence of brain lesions that significantly hinders rehabilitation. This review analyzes current non-invasive BCIs and technological solutions dedicated to cognitive rehabilitation, with a focus on visuo-attentional disorders. We emphasize the need for further research into the use of BCIs for managing cognitive impairments and propose a new potential solution for USN rehabilitation, by combining the clinical subtleties of this syndrome with the technological advancements made in the field of neurotechnologies.

Spatial Neglect: An Exploration of Clinical Assessment Behaviour in Stroke Rehabilitation

OBJECTIVE

There is a large gap between evidence-based recommendations for spatial neglect assessment and clinical practice in stroke rehabilitation. We aimed to describe factors that may contribute to this gap, clinician perceptions of an ideal assessment tool, and potential implementation strategies to change clinical practice in this area.

DESIGN

Qualitative focus group investigation. Focus group questions were mapped to the Theoretical Domains Framework and asked participants to describe their experiences and perceptions of spatial neglect assessment.

SETTING

Online stroke rehabilitation educational bootcamp.

PARTICIPANTS

A sample of 23 occupational therapists, three physiotherapists, and one orthoptist that attended the bootcamp.

INTERVENTION

Prior to their focus group, participants watched an hour-long educational session about spatial neglect.

MAIN MEASURES

A deductive analysis with the Theoretical Domains Framework was used to describe perceived determinants of clinical spatial neglect assessment. An inductive thematic analysis was used to describe perceptions of an ideal assessment tool and practice-change strategies in this area.

RESULTS

Participants reported that their choice of spatial neglect assessment was influenced by a belief that it would positively impact the function of people with stroke. However, a lack of knowledge about spatial neglect assessment appeared to drive low clinical use of standardised functional assessments. Participants recommended open-source online education involving a multidisciplinary team, with live-skill practice for the implementation of spatial neglect assessment tools.

CONCLUSIONS

Our results suggest that clinicians prefer functional assessments of spatial neglect, but multiple factors such as knowledge, training, and policy change are required to enable their translation to clinical practice.

The line bisection bias as a deficit of proportional reasoning - evidence from number line estimation in neglect

This study aimed to investigate whether neurological patients presenting with a bias in line bisection show specific problems in bisecting a line into two equal parts or their line bisection bias rather reflects a special case of a deficit in proportional reasoning more generally. In the latter case, the bias should also be observed for segmentations into thirds or quarters. To address this question, six neglect patients with a line bisection bias were administered additional tasks involving horizontal lines (e.g., segmentation into thirds and quarters, number line estimation, etc.). Their performance was compared to five neglect patients without a line bisection bias, 10 patients with right hemispheric lesions without neglect, and 32 healthy controls. Most interestingly, results indicated that neglect patients with a line bisection bias also overestimated segments on the left of the line (e.g., one third, one quarter) when dissecting lines into parts smaller than halves. In contrast, such segmentation biases were more nuanced when the required line segmentation was framed as a number line estimation task with either fractions or whole numbers. Taken together, this suggests a generalization of line bisection bias towards a segmentation or proportional processing bias, which is congruent with attentional weighting accounts of line bisection/neglect. As such, patients with a line bisection bias do not seem to have specific problems bisecting a line, but seem to suffer from a more general deficit processing proportions.

A systematic review of vestibular stimulation in post-stroke visual neglect

Unilateral visual neglect is a condition that negatively impacts the lives of many stroke survivors. Studies have investigated different forms of vestibular stimulation as a potential therapy, but evidence is yet to be systematically reviewed. We therefore reviewed the effects of vestibular stimulation on outcomes of neglect and activities of daily living (ADL) for people with visual neglect. We searched relevant databases up until September 2022. Eligible articles included any form of vestibular stimulation, study design, or control condition. Included participants were 18 years or older, presenting with neglect following a haemorrhagic or ischaemic stroke. Relevant outcomes were clinically validated measures of neglect and ADL. Cochrane risk of bias tools were used to assess study quality. Meta-analyses and narrative methods were used to synthesize the data. Our search returned 17 relevant studies comprising 180 participants. Meta-analyses showed no difference between galvanic vestibular stimulation and sham conditions on outcomes, whereas caloric vestibular stimulation led to improvement compared to pre-stimulation scores. Narrative syntheses showed mixed results. Clinical and methodological heterogeneity was found both within and between studies. Overall, results were inconsistent regarding the effects of vestibular stimulation as a treatment for neglect. Further trials are warranted but require more careful methodological planning.

Understanding Occupational Therapists' Knowledge and Confidence When Assessing for Spatial Neglect: A Special Issue Review

IMPORTANCE

Spatial neglect (SN)-failure to respond to stimuli on the side of the body contralateral to a poststroke lesion-is one of the most disabling impairments for stroke survivors, and 80% of stroke survivors may have undetected SN. Occupational therapists' evaluations should include determining the impact of poststroke SN.

OBJECTIVE

To investigate occupational therapists' confidence, knowledge, current practices, barriers, and facilitators when assessing for SN in adult stroke survivors.

DESIGN

A 30-item survey was created with guidance from stroke rehabilitation occupational therapists who reviewed the survey for face and content validity.

SETTING

Online survey.

PARTICIPANTS

Occupational therapist survey responders (N = 76).

OUTCOMES AND MEASURES

Self-report assessments were used to measure occupational therapists' confidence in identifying SN, SN assessment practices, and barriers to and facilitators of SN assessment. Knowledge of SN signs and symptoms, neuroanatomy, and clinical presentation were measured with a three-question quiz.

RESULTS

Eighty-one percent of the respondents reported a high level of confidence in identifying SN, and 70% reported routinely assessing for SN, with 81% using clinical observation rather than standardized tools as the primary assessment method. Barriers to SN assessment included time and resources.

CONCLUSIONS AND RELEVANCE

Most respondents, despite reporting high levels of confidence with routine SN assessments, did not use standardized SN measures and demonstrated suboptimal knowledge of SN. These results emphasize the need to increase clinical education about SN and its assessments. Plain-Language Summary: This study gathered baseline information on an underinvestigated topic-occupational therapists' education, confidence, current practices, barriers, and facilitators when assessing for spatial neglect in adult stroke survivors. The study results also contribute to future research on occupational therapists' current confidence and knowledge when assessing for spatial neglect.

The Association of Personal Neglect with Motor, Activities of Daily Living, and Participation Outcomes after Stroke: A Systematic Review

Despite its potential clinical impact, the association of personal neglect (PN) with motor, activities of daily living (ADL), and participation outcomes after stroke is not well-understood. This first-ever systematic review on the topic therefore evaluates this association, taking into account suggested subtypes of PN, including body representation neglect, somatosensory neglect, motor neglect, and premotor neglect. A systematic literature search was conducted on February 17, 2023 in PubMed, Web of Science, Scopus, PubPsych, and PsycArticles databases. The study adheres to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and its protocol was registered on PROSPERO (CRD42020187460). Eleven observational studies were included, gathering 1,400 individuals after stroke (429 showed PN). Results show that individuals with body representation neglect after stroke have significantly decreased movement control and motor strength, lower functional mobility, and ADL independency compared with those without body representation neglect after stroke. Individuals with motor neglect after stroke showed worse motor function and spasticity than to those without motor neglect after stroke. Nonspecified PN (i.e., PN evaluated with an outcome measure that does not allow subcategorization) was related to worse lateropulsion with pushing, longer length of stay and greater odds of being discharged to somewhere other than home. No study evaluated somatosensory and premotor neglect. This review highlights the limited research in this area and emphasizes the need for a more comprehensive PN assessment. However, currently available assessment tools show limited ability to accurately diagnose PN subtypes and future research should prioritize the development of comprehensive diagnostic test batteries.

Identifying Spatial Neglect in Chronic Right Hemisphere Stroke Survivors Using the RHDBank Outcomes

PURPOSE

The chronicity of spatial neglect (SN) and the utility of existing diagnostic measures used by speech-language pathologists remain poorly understood. In this retrospective study, we examined how the RHDBank test battery informs the identification of SN after right hemisphere brain damage (RHD) during the chronic phase of recovery.

METHOD

Data from 29 right hemisphere stroke survivors were extracted from the RHDBank, including SN tests, for which we performed laterality index scoring: a 51-item demographic survey, the Apples Test, the Indented Paragraph Test, and the clock drawing task from the Cognitive Linguistic Quick Test (CLQT). Two groups (SN+ and SN-) were identified using the Apples Test. A hierarchical cluster analysis explored CLQT performance clusters in association with SN, and group comparisons of demographic variables and test scores were conducted.

RESULTS

Ten patients were identified as having SN+ (34%) using the Apples Test. The Indented Paragraph Test and the CLQT's clock drawing test identified only two of the 20 stroke survivors with SN+. Cluster analyses showed that domain and task scores on the CLQT carried information to classify participants into SN+ and SN- in concordance with performance on the Apples Test. Participants in the SN+ cluster had moderately impaired attention and executive function skills and mildly impaired visuospatial skills.

CONCLUSIONS

The Apples Test differentiated SN in a group of chronic right hemisphere stroke survivors. Using multiple measures from the CLQT seemed to capture a greater range of problems than clock drawing and paragraph reading tests alone. Therefore, the RHDBank test battery as a whole-and in part the CLQT, Apples Test, and Indented Paragraph Test-can detect certain subtypes of SN in the chronic deficit profile after RHD and is a starting point for diagnostic integration by speech-language pathologists.

Virtual reality tasks with eye tracking for mild spatial neglect assessment: a pilot study with acute stroke patients

Objective

Increasing evidence shows that traditional neuropsychological tests are insensitive for detecting mild unilateral spatial neglect (USN), lack ecological validity, and are unable to clarify USN in all different spatial domains. Here we present a new, fully immersive virtual reality (VR) task battery with integrated eye tracking for mild visual USN and extinction assessment in the acute state of stroke to overthrow these limitations.

Methods

We included 11 right-sided stroke patients and 10 healthy controls aged 18-75 years. Three VR tasks named the Extinction, the Storage and the Shoot the target tasks were developed to assess USN. Furthermore, neuropsychological assessment examining various parts of cognitive functioning was conducted to measure general abilities. We compared VR and neuropsychological task performance in stroke patients - those with (USN+, n = 5) and without USN (USN-, n = 6) - to healthy controls (n = 10) and tentatively reported the usability of VR system in the acute state of stroke.

Results

Patients had mostly mild neurological and USN symptoms. Nonetheless, we found several differences between the USN+ and healthy control groups in VR task performance. Compared to controls, USN+ patients showed visual extinction and asymmetry in gaze behavior and detection times in distinct spatial locations. Extinction was most evident in the extrapersonal space and delayed detection times on the extreme left and on the left upper parts. Also, USN+ patients needed more time to complete TMT A compared with USN- patients and TMT B compared with controls. VR system usability and acceptance were rated high; no relevant adverse effects occurred.

Conclusion

New VR technology with eye tracking enables ecologically valid and objective assessment methods with various exact measures for mild USN and thus could potentially improve future clinical assessments.

Task-based and Magnified Mirror Therapy for Unilateral Spatial Neglect among post-stroke subjects: Study protocol for a randomized controlled trial

BACKGROUND

Unilateral spatial neglect (USN) is a commonly occurring neurocognitive disability after a stroke. The neglect may affect the motor recovery of the upper and lower limbs and functional performances. Mirror therapy, a simple and economical approach has the potential to reduce the USN and related impairments.

AIM

The primary objective of this study is to determine the effectiveness of task-based and magnified mirror therapy on the USN and on the motor recovery of the post-stroke subjects. The secondary objective is to investigate the effectiveness of the intervention on the function and disability of the subjects.

METHODS

In this randomized controlled, assessor-blinded trial, 86 post-stroke subjects will be recruited from the neuro-rehabilitation laboratory of a rehabilitation institute, located in northern India. The participants,aged20 to 80 years, with 1 to 36 months of stroke onset, hemiparesis, and the USN, will be considered eligible for the study. In addition to the conventional rehabilitation, the experimental group(n = 43) will receive 40 sessions (8 weeks) of Task-based and MAGnified Mirror Therapy for Unilateral Spatial Neglect (T-MAGUSN). The control group (n = 43) will undergo a dose-matched conventional program only. The participants will be assessed at baseline, post-intervention and 4-week follow-up using primary (Line Bisection Test, Letter Cancellation Test, and Fugl-Myer Assessment) and secondary (Catherine Bergego Scale, Berg Balance Scale, Functional Ambulation Classification, Modified Rankin Scale) outcome measures.

DISCUSSION

This proposed study will lead to the development of a novel rehabilitation protocol for the management of USN, aiming to enhance motor and functional recovery. The investigation will consider both the upper and lower limbs for the intervention, reducing the impact of cognitive disability in stroke.

TRIAL REGISTRATION

Clinical Trial Registry of India (CTRI) as CTRI/2023/05/053184 (www.ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=74659).

Impact of Spatial Neglect on Activity and Participation: A Mixed-Methods Study

Post-stroke neglect is disabling, yet it is unclear whether existing assessments capture the extent neglect affects activity and participation. The objective of the study is to explore stroke survivor and caregiver perspectives on how neglect affects activity and participation and to compare their experiences to neglect assessments items. We conducted an explanatory sequential mixed-methods study by conducting semi-structured interviews with stroke survivors (n = 7) and caregivers (n = 7) analyzed using thematic analysis. Stroke survivors completed the Catherine Bergego Scale (CBS) and Behavioral Inattention Test (BIT). Descriptive analyses characterized participant's neglect. The standardized CBS and BIT tests indicated that stroke survivors demonstrated mild-to-moderate (CBS) or no-to-mild (BIT) neglect. In contrast, the qualitative data revealed serious safety concerns and significant ongoing difficulties participating in school, work, and family activities because of neglect. Current assessments may not measure the impact of neglect on activity or participation in life for stroke survivors.

Prevalence, Severity and Impact of Visuospatial Neglect in Geriatric Stroke Rehabilitation, a Cross-Sectional Study

OBJECTIVES

Visuospatial neglect (VSN) is a common cognitive deficit of lateralized attention after stroke and can have a negative influence on patients' daily activities, community participation, and caregiver burden. VSN prevalence has been investigated in several mixed-age populations, but rarely in only an older population. As the population in geriatric rehabilitation (GR) is understudied and VSN may influence rehabilitation goals in GR (return home), we examined the prevalence of VSN as well as associations between VSN (severity) and population characteristics and the impact of VSN on functioning, length of stay, and discharge destination after GR.

DESIGN

Multicenter cross-sectional study.

SETTING AND PARTICIPANTS

Stroke patients admitted to GR.

METHODS

Three VSN tests (Star cancelation task, Line bisection task, and Catherine Bergego Scale) were administered in the first 2 weeks of GR admission. To examine VSN severity, a composite score was calculated based on scores of the 3 tests.

RESULTS

A total of 114 stroke patients were included [55.3% female; mean age 80.2 (SD 8.0) years]. VSN prevalence was 47.4%, in which allocentric and egocentric neglect were more prevalent than VSN during activities of daily living. Participants with VSN spent more days in GR compared to participants without VSN (median 68.5 vs 35.5 days) and had fewer home returns. In addition, VSN participants showed less mobility, lower cognitive functioning, and less independence during self-care compared to participants without VSN. Mobility, self-care, cognition, duration of rehabilitation, and home return were negatively associated with VSN severity.

CONCLUSIONS AND IMPLICATIONS

VSN is very prevalent in the GR stroke population. VSN severely hampers older people during daily activities and their rehabilitation process and, therefore, has a major personal and societal impact. Accordingly, systematic assessment of VSN in the early phase of geriatric rehabilitation with multiple VSN screening tests is recommended.

Sensitivity and Specificity of the Brentano Illusion Test in the Detection of Visual Hemi-Field Deficits in Patients with Unilateral Spatial Neglect

Stroke survivors with right-brain damage (RBD) often present with attentional deficits such as left unilateral spatial neglect. Some patients also present with contralesional visual hemi-field deficits. A late detection of visual hemi-field deficits (VHFD) contributes to hampering neurorehabilitation and functional outcome of patients with neglect. The Brentano Illusion Test (BRIT) may be used for an early detection of VHFD during the neuropsychological assessment. In the present study, we determined the sensitivity and specificity of the BRIT for screening VHFD in patients with neglect. Sixty-four consecutive RBD patients were examined. Forty-five presented with neglect. Of these, 23 presented with VHFD (hemianopia or quadrantanopia) as detected by the Humphrey automated static visual field testing (reference standard). Consecutive patients also included 19 participants without neglect, who did not have any VHFD. The sensitivity and specificity of the BRIT for neglect patients were 78.3% (95% CI: 61.4-95.1) and 90.9 (95% CI: 78.9-100.0), respectively. Positive predictive value (PPV) was 89.6% (95% CI: 76.4-100.0); negative predictive value (NPV) 80.7% (95% CI: 65.2-96.2). No false positives in the group without neglect were identified. We conclude that the BRIT is an effective tool for clinical neuropsychologists to screen for possible VHFD in neglect patients during the neuropsychological assessment, allowing the refinement of the clinical picture in the neuropsychological report. An early detection of VHFD also allows referring the patient to standard diagnostics for a formal visual field examination, right from the first neuropsychological assessment.

Broken Ring enVision Search (BReViS): A New Clinical Test of Attention to Assess the Effect of Layout and Crowding on Visual Search

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients.